Midfield has usually been Liverpool's most worrying component so far this season, but thanks to Enrique's ongoing knee injury – which now looks like it'll require surgery – Liverpool's defense might well be the greater concern tomorrow. Because it's not as if Liverpool are spoiled for options at full-back.

Aly Cissokho has been – to put it mildly – not good, not good at all, in his four starts this season.

Personally, I'd start Agger on the left with Skrtel and Sakho in the middle. Sakho at left-back didn't work against Southampton, but Agger would seemingly be more comfortable in the position. The full-back opposite Johnson has almost always been the more restrained, more defensive so far this season, and Agger could certainly do a job doing that. It'd also allow Sakho to come back into the XI without removing Liverpool's vice captain, and he's almost certainly on a high after his starring role in France's World Cup qualifier on Tuesday. Plus, Agger's long throws. Long throws are always fun.

But Rodgers sees it differently, with today's quotes making Flanagan at left-back look the most likely option if Rodgers has also completely lost faith with Cissokho. You'd think the opposite would be the case: Flanagan on the right, Johnson on the left – which we've seen in the past – but keeping Johnson on his preferred side makes a certain amount of sense. Liverpool's attack tilted heavily toward that flank against Fulham, and doing the same against Everton should help restrain Baines' forays forward. As Liverpool heavily favor its right flank, Everton heavily favor its left. Flanagan did adequately against Arsenal before being replaced with Liverpool needing more in attack, and his discipline should also help to restrain Kevin Mirallas, Everton's leader in assists so far this season and a player frequently looking to cut inside, which would put him against Flanagan's stronger foot.

Both Skrtel and Agger struggled against Lukaku last season, used as a substitute and scoring the final goal in both of West Brom's wins against Liverpool. But those two defenders still make the most sense if Liverpool continue with four at the back. Skrtel has been Liverpool's best center-back this season, back on the peak these season after wandering through the valley last season. Rodgers should and almost certainly will ride this form while it lasts. Agger, despite a handful of errors, remains Liverpool's best defender when in possession, crucial to building from the back. Both Sakho and Toure are excellent stand-ins, and I'm tempted to suggest that Sakho may return given his prowess in the air against Lukaku and his international break form, but, as usual, I'll almost always stick with the devil you know in Merseyside derbies. I highly, highly doubt that Liverpool will revert to the three-at-the-back with wing-backs system with Everton so dangerous on the flanks.

There are also concerns about Sturridge's fitness, hampered by a dead leg over the last month yet featuring for the full 90 minutes in England's meaningless friendly against Germany on Tuesday. If he's unable to start, Liverpool will almost certainly shift to the 4-2-3-1 formation, most likely with Lucas, Gerrard; Henderson, Coutinho, Moses; Suarez as the front six. Still, you have to assume that Sturridge will start if at all possible. He and Suarez are the biggest reasons why Liverpool are currently second in the table.

Upgrading Everton's midfield has been the biggest boon. Both McCarthy and Barry have been excellent signings so far: more comfortable recycling play and keeping possession, less likely to punt the ball upfield and hope for the best or just push it sideways so Baines can create something, anything. Gibson and Osman, last season's most-frequent midfield combination, averaged just under 100 passes per match, successful with 84.3% of them. McCarthy and Barry are averaging just under 125 at 86.6% accuracy. They're also averaging around two more tackles per match than Osman and Gibson did last season.

But Everton are still goal-shy at times. The Blues have already played four 0-0 draws through 11 league matches, including two in their last two games, equalling their total through all of last season. Sam Allardyce's West Ham – a manager renowned for smothering absolutely all the joy out of football matches – are the only other side with that many scoreless draws. No other side has three, only four other sides have played two. Liverpool, along with Arsenal, Fulham, and Sunderland, have yet to play one. Not coincidentally, Liverpool and Everton fumbled their way to a 0-0 draw in the last meeting, with both sides eminently poor in attack.

I'd be surprised if Everton's XI wasn't Howard; Coleman, Jagielka, Distin, Baines; McCarthy, Barry; Mirallas, Osman, Pienaar; Lukaku. Martinez may prefer Barkley to Osman, as he did earlier in the season, but otherwise, he's stayed fairly consistent with his selection.

Away from home, against a side comfortable in possession, Liverpool will need to replicate the potent heavy pressing deployed against Fulham, preventing Barry and McCarthy from dominating the ball and allowing Everton to build a head of steam before bringing in its dangerous attackers. Reclaim possession, then quick transitions to Coutinho, Suarez, and Sturridge, perpetually dangerous on the counter, especially away from home. Three of Everton's most important players – Barry, McCarthy, Lukaku – have never featured in a Merseyside derby, and two of those players will be relied upon to set Everton's tempo.

That said, no matter the personnel involved, Merseyside derbies remain unpredictable animals, rarely fitting into the easy, expected narratives. War metaphors are often embarrassingly, unnecessarily used in sports, but they usually feel appropriate when describing these fixtures. Even considering Rodgers and Martinez's respective progressive philosophies, I doubt that'll change much tomorrow.